Utilizing phase change material, heat pipes, and fuel cells for aircraft applications

ABSTRACT

A heat transfer system includes a fuel cell module that produces heat and water, and a thermal energy storage module that stores the heat produced by the fuel cell module. The thermal energy storage module includes a phase-change material. A conduit couples the fuel cell module to the thermal energy storage module. The conduit is oriented to channel the water produced by the fuel cell module through the thermal energy storage module.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional and claims priority to U.S. patentapplication Ser. No. 13/357,254 filed Jan. 24, 2012 for “UTILIZING PHASECHANGE MATERIAL, HEAT PIPES, AND FUEL CELLS FOR AIRCRAFT APPLICATIONS”,which is hereby incorporated by reference in its entirety.

BACKGROUND

The present disclosure relates generally to heat transfer systems and,more particularly, to methods and systems for utilizing thermal energyin the form of heat produced by a fuel cell module and/or utilizing heatstored in a phase change material thermal energy storage module.

Known aircraft include a plurality of engines that generate liftingpower. At least some known aircraft include electrical components thatrequire electricity to operate. To provide electricity to suchelectrical components, at least some known aircraft extract power fromthe engines. However, supplying electricity from the engines to theelectrical components increases an overall fuel consumption of theengine. To facilitate reducing electrical demand from the engines, atleast some known aircraft include fuel cells that generate power for usein powering onboard electrical components. However, at least some knownaircraft do not efficiently utilize electricity and/or byproductsgenerated by the fuel cell.

BRIEF SUMMARY

In at least one other aspect, a method for operating a heat transfersystem is provided. The method includes coupling a plurality of heatpipes to the load. Heat is transferred to a thermal energy storagemodule including a phase-change material. The heat is stored in thethermal energy storage module. The thermal energy storage module iscoupled to the plurality of heat pipes to facilitate transferring heattowards the load.

In at least one other aspect, a heat transfer system is provided. Theheat transfer system includes a load, and a plurality of heat pipescoupled to the load. A thermal energy storage module is coupled to theplurality of heat pipes to facilitate transferring heat towards theload. The thermal energy storage module includes a phase-changematerial.

In at least one other aspect, a method for operating a heat transfersystem is provided. The method includes transferring heat to a thermalenergy storage module including a phase-change material. The heat isstored in the thermal energy storage module. The thermal energy storagemodule is circumscribed about the load to facilitate transferring heattowards the load.

In at least one other aspect, a heat transfer system is provided. Theheat transfer system includes a load, and a thermal energy storagemodule circumscribing the load to facilitate transferring heat towardsthe load. The thermal energy storage module includes a phase-changematerial.

In at least one other aspect, an aircraft is provided. The aircraftincludes a galley including at least one load positioned therein, a fuelcell module configured to produce heat and water, and a heat transfersystem. The heat transfer system includes a first plurality of heatpipes coupled to the at least one load and a thermal energy storagemodule coupled to the first plurality of heat pipes to facilitatetransferring the heat produced by the fuel cell module towards the atleast one load. The thermal energy storage module includes aphase-change material.

The features, functions, and advantages described herein may be achievedindependently in various embodiments of the present disclosure or may becombined in yet other embodiments, further details of which may be seenwith reference to the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of an exemplary aircraft;

FIGS. 2-7 are schematic illustrations of exemplary heat transfer systemsthat utilize heat produced by a fuel cell module; and

FIGS. 8-13 are schematic illustrations of exemplary heat transfersystems that utilize heat stored in a thermal energy storage module.

Although specific features of various embodiments may be shown in somedrawings and not in others, this is for convenience only. Any feature ofany drawing may be referenced and/or claimed in combination with anyfeature of any other drawing.

DETAILED DESCRIPTION

The subject matter described herein relates generally to heat transfersystems and, more particularly, to methods and systems for utilizingheat produced by a fuel cell module and/or for utilizing heat stored ina thermal energy storage module. In one embodiment, a fuel cell moduleproduces electricity, heat, and water. A thermal energy storage moduleincluding a phase-change material stores the heat produced by the fuelcell module. A conduit coupling the fuel cell module to the thermalenergy storage module channels water through the thermal energy storagemodule. As such, the thermal energy storage module is positioned tofacilitate cooling the fuel cell module, and the water is used tofacilitate cooling the thermal energy storage module.

As used herein, the term “load” or “external load” refers to any deviceand/or machine that utilizes electricity, heat, water, and/or any otherbyproduct generated, created, and/or produced by another device and/ormachine. An element or step recited in the singular and proceeded withthe word “a” or “an” should be understood as not excluding pluralelements or steps unless such exclusion is explicitly recited. Moreover,references to “one embodiment” of the present invention and/or the“exemplary embodiment” are not intended to be interpreted as excludingthe existence of additional embodiments that also incorporate therecited features.

FIG. 1 is a plan view of an exemplary aircraft 100. In the exemplaryembodiment, aircraft 100 includes a body 110 that includes a fuselage120 and a pair of wings 130 extending from fuselage 120. In theexemplary embodiment, at least one engine 140 is coupled to each wing130 to provide thrust for aircraft 100. Aircraft 100 may include anynumber of engines 140 that enables aircraft 100 to function as describedherein. In the exemplary embodiment, aircraft 100 includes at least onecomponent and/or structure that is fabricated from a composite material.

FIG. 2 is a schematic illustration of an exemplary heat transfer system200 that may be used to utilize heat produced by a fuel cell module 202on and/or within aircraft 100 (shown in FIG. 1). In the exemplaryembodiment, fuel cell module 202 is a device that converts fuel 204 andoxidants 206 into electricity 208 that may be used within aircraft 100.In the exemplary embodiment, electricity 208 is used to run, forexample, a water pump 210 (i.e., an external load). Other external loadsthat may run on electricity 208 include, without limitation, a coffeemachine and/or an oven. In the exemplary embodiment, fuel cell module202 produces water 212 and thermal energy or heat 214.

In the exemplary embodiment, at least one conduit 216 couples fuel cellmodule 202 in flow communication with a thermal energy storage module218. In the exemplary embodiment, thermal energy storage module 218includes a plurality of heat pipes 220 and a phase-change material (PCM)222. Moreover, in the exemplary embodiment, heat pipes 220 are coupledto fuel cell module 202 to facilitate passively transferring heat 214between fuel cell module 202 and PCM 222. Furthermore, in the exemplaryembodiment, at least one insulating layer 224 substantiallycircumscribes fuel cell module 202 and/or thermal energy storage module218 to facilitate decreasing heat loss to the ambient environment.

In the exemplary embodiment, heat pipes 220 reduce the thermalresistance within PCM 222 to facilitate increasing the heat transferrate and/or the efficiency between fuel cell module 202 and thermalenergy storage module 218. For example, in at least some embodiments,heat pipes 220 are fabricated from, for example, copper, aluminum,and/or steel and include working fluids operating between approximately0° C. and approximately 200° C. More particularly, in at least someembodiments, the working fluids operate between approximately 25° C. andapproximately 200° C. Even more particularly, in at least someembodiments, the working fluids operate between approximately 25° C. andapproximately 160° C. Working fluids for use in heat pipes 220 mayinclude, without limitation, water and/or methanol. Moreover, in atleast some embodiments, heat pipes 220 include a wick structure that isfabricated from, for example, sintered metal powder, metal fibers,and/or screen mesh. Alternatively, heat pipes 220 may be fabricated fromany other material and/or include any other fluid that enable heattransfer system 200 to function as described herein. For example, in atleast one embodiment, heat pipes 220 are in a vertical orientation andare gravity assisted.

Generally, heat 214 is transferred from fuel cell module 202 towards PCM222, which melts as it absorbs heat 214. In the exemplary embodiment,PCM 222 has a melting point between approximately 10° C. andapproximately 100° C., depending on the fuel cell operating temperaturerange. For example, in at least some embodiments, fuel cell module 202operates at a temperature between approximately 50° C. and approximately160° C. More particularly, in at least some embodiments, fuel cellmodule 202 operates at a temperature between approximately 100° C. andapproximately 160° C. In at least some embodiments, PCM 222 isfabricated from an organic material, such as paraffin wax, fatty acid,and/or sugar alcohol, and/or from an inorganic material, such as moltensalt, salt hydrate, and/or another salt mixture. Alternatively, PCM 222may be fabricated from any other material that enable heat transfersystem 200 to function as described herein.

In the exemplary embodiment, heat transfer system 200 regulates and/ormanages a temperature of water 212 and/or thermal energy storage module218. In the exemplary embodiment, heat transfer system 200 includes afirst storage tank 226 positioned to store water 212. More specifically,in the exemplary embodiment, storage tank 226 is coupled in flowcommunication between fuel cell module 202 and thermal energy storagemodule 218 such that water 212 discharged from fuel cell module 202 ischanneled into storage tank 226 and subsequently channeled towardsthermal energy storage module 218. In the exemplary embodiment, conduit216 is positioned and/or oriented to channel water 212 through thermalenergy storage module 218 towards, for example, a sink 228 (i.e., anexternal load). In the exemplary embodiment, thermal energy storagemodule 218 is removably coupled to sink 228.

In the exemplary embodiment, heat transfer system 200 includes a secondwater system 230 including potable water 232 that is not generally mixedwith water 212. In the exemplary embodiment, heat transfer system 200regulates and/or controls a temperature of potable water 232 and/orthermal energy storage module 218. In the exemplary embodiment, heattransfer system 200 includes a second storage tank 234 positioned tostore potable water 232. In the exemplary embodiment, potable water 232is channeled from second storage tank 234 through thermal energy storagemodule 218 and towards, for example, coffee machine 236 (i.e., anexternal load).

During operation, fuel cell module 202 receives fuel 204 and oxidants206 and generates and/or produces electricity 208, water 212, and/orheat 214. In the exemplary embodiment, at least some fuel 204 may bedischarged from fuel cell module 202 for reuse in fuel cell module 202.In the exemplary embodiment, heat pipes 220 absorb heat 214 from fuelcell module 202, and PCM 222 stores heat 214.

In the exemplary embodiment, water 212 and oxidants 206 are dischargedfrom fuel cell module 202 towards storage tank 226, wherein oxidants 206are separated from water 212. In the exemplary embodiment, at least someoxidants 206 may be discharged from storage tank 226 for reuse in fuelcell module 202. In the exemplary embodiment, water pump 210 draws water212 and/or 232 from a respective storage tank 226 and/or 234 anddischarges water 212 and/or 232 towards thermal energy storage module218. In at least one embodiment, water 212 is mixed with other waterwithin storage tank 226 to facilitate reducing a temperature of water212.

In the exemplary embodiment, as water 212 and/or 232 is channeledthrough thermal energy storage module 218, heat 214 is transferred fromthermal energy storage module 218 to water 212 and/or 232 such that atemperature of thermal energy storage module 218 is facilitated to bedecreased and a temperature of water 212 and/or 232 is facilitated to beincreased. That is, in the exemplary embodiment, water 212 and/or 232cools thermal energy storage module 218 to enable thermal energy storagemodule 218 to absorb heat 214 from fuel cell module 202, and thermalenergy storage module 218 heats water 212 and/or 232 for use in, forexample, sink 228 and/or coffee machine 236 (i.e., external loads).

FIG. 3 is a schematic illustration of another exemplary heat transfersystem 300 that may be used to utilize heat produced by fuel cell module202 on and/or within aircraft 100 (shown in FIG. 1). In the exemplaryembodiment, heat transfer system 300 is generally similar to heattransfer system 200, but includes a filter 338 configured to convertwater 212 discharged by fuel cell module 202 into potable water 232.That is, in the exemplary embodiment, filter 302 is configured tofacilitate increasing a drinking quality of the water channeledtherethrough.

In the exemplary embodiment, filter 302 is positioned serially betweenfuel cell module 202 and a first storage tank 340. In the exemplaryembodiment, storage tank 340 is positioned such that potable water 232is channeled towards storage tank 340 and subsequently channeled towardsthermal energy storage module 218. In the exemplary embodiment, heattransfer system 300 includes a second water system 342 including asecond storage tank 344 and water 212 that is not generally mixed withwater 232.

During operation, fuel cell module 202 receives fuel 204 and oxidants206 and generates and/or produces electricity 208, water 212, and/orheat 214. In the exemplary embodiment, at least some fuel 204 may bedischarged from fuel cell module 202 for reuse in fuel cell module 202.In the exemplary embodiment, heat pipes 220 absorb heat 214 from fuelcell module 202, and PCM 222 stores heat 214.

In the exemplary embodiment, water 212 and oxidants 206 are dischargedfrom fuel cell module 202 towards filter 302. In the exemplaryembodiment, filter 302 converts water 212 into potable water 232, andpotable water 232 is discharged towards storage tank 340, whereinoxidants 206 are separated from potable water 232. In the exemplaryembodiment, at least some oxidants 206 may be discharged from storagetank 340 for reuse in fuel cell module 202. In at least one embodiment,potable water 232 is mixed with other water within storage tank 340 tofacilitate reducing a temperature of water 232. In the exemplaryembodiment, water pump 210 draws water 212 and/or 232 from storage tank344 and/or 340, respectively, and discharges water 212 and/or 232towards thermal energy storage module 218.

In the exemplary embodiment, heat 214 is transferred from thermal energystorage module 218 to water 212 and/or 232 as water 212 and/or 232 ischanneled through thermal energy storage module 218 such that atemperature of thermal energy storage module 218 is facilitated to bedecreased and a temperature of water 212 and/or 232 is facilitated to beincreased. That is, in the exemplary embodiment, water 212 and/or 232cools thermal energy storage module 218 to enable thermal energy storagemodule 218 to absorb heat 214 from fuel cell module 202, and thermalenergy storage module 218 heats water 212 and/or 232 for use in, forexample, sink 228 and/or coffee machine 236 (i.e., external loads).

FIG. 4 is a schematic illustration of another exemplary heat transfersystem 400 that may be used to utilize heat produced by a fuel cellmodule 202 on and/or within aircraft 100 (shown in FIG. 1). In theexemplary embodiment, electricity 208 is used to run, for example, waterpump 210, coffee machine 236, and/or oven 446.

In the exemplary embodiment, heat transfer system 200 includes a storagetank 448 positioned to store water 212. More specifically, in theexemplary embodiment, storage tank 448 is positioned adjacent thermalenergy storage module 218 such that water 212 discharged from fuel cellmodule 202 is channeled towards storage tank 448, wherein water 212 isheated by thermal energy storage module 218. In the exemplaryembodiment, a filter 450 is positioned downstream from storage tank 448and is configured to convert water 212 discharged from storage tank 448into potable water 232. That is, in the exemplary embodiment, filter 450is configured to facilitate increasing a drinking quality of the waterchanneled therethrough. In the exemplary embodiment, filter 450 ispositioned serially between storage tank 448 and, for example, sink 228and/or coffee machine 236 (i.e., external loads).

During operation, fuel cell module 202 receives fuel 204 and oxidants206 and generates and/or produces electricity 208, water 212, and/orheat 214. In the exemplary embodiment, at least some fuel 204 may bedischarged from fuel cell module 202 for reuse in fuel cell module 202.In the exemplary embodiment, heat pipes 220 absorb heat 214 from fuelcell module 202, and PCM 222 stores heat 214.

In the exemplary embodiment, water 212 and oxidants 206 are dischargedfrom fuel cell module 202 towards storage tank 448, wherein oxidants 206are separated from water 212. In the exemplary embodiment, at least someoxidants 206 may be discharged from storage tank 448 for reuse in fuelcell module 202. In at least one embodiment, tank 448 includes coldwater and absorbs heat from fuel cell module 202 during operation. Insuch an embodiment, water 212 is mixed with the cold water within tank448 to facilitate reducing a temperature of water 212. In the exemplaryembodiment, heat 214 is transferred from thermal energy storage module218 to water 212 as water 212 is stored within storage tank 448 suchthat a temperature of thermal energy storage module 218 is facilitatedto be decreased and a temperature of water 212 is facilitated to beincreased. That is, in the exemplary embodiment, water 212 cools thermalenergy storage module 218 to enable thermal energy storage module 218 toabsorb heat 214 from fuel cell module 202, and thermal energy storagemodule 218 heats water 212 for use in, for example, sink 228 and/orcoffee machine 236 (i.e., external loads).

In the exemplary embodiment, water pump 210 draws water 212 from storagetank 448 and discharges water 212 towards filter 450. In the exemplaryembodiment, filter 450 converts water 212 into potable water 232, andpotable water 232 is discharged towards, for example, sink 228 and/orcoffee machine 236 (i.e., external loads).

FIG. 5 is a schematic illustration of another exemplary heat transfersystem 500 that may be used to utilize heat produced by a fuel cellmodule 202 on and/or within aircraft 100 (shown in FIG. 1). In theexemplary embodiment, fuel cell module 202 is integrally coupled to athermal energy storage module 552 that includes a plurality of heatpipes 554 and PCM 222. In the exemplary embodiment, thermal energystorage module 552 substantially circumscribes fuel cell module 202 tofacilitate decreasing heat loss to the ambient environment. Moreover, inthe exemplary embodiment, at least one insulating layer 556substantially circumscribes fuel cell module 202 and/or thermal energystorage module 552 to facilitate decreasing heat loss to the ambientenvironment. In the exemplary embodiment, heat pipes 554 are generallysimilar to heat pipes 220. Alternatively, heat pipes 554 may befabricated from any other material and/or include any other fluid thatenable heat transfer system 500 to function as described herein.

In the exemplary embodiment, heat pipes 552 are coupled to fuel cellmodule 202 to facilitate passively transferring heat 214 between fuelcell module 202 and PCM 222. More specifically, in the exemplaryembodiment, fuel cell module 202 includes a plurality of bipolar plates558 positioned in series circuit and/or in parallel circuit. In theexemplary embodiment, each plate 558 has a first plurality of channels560 configured to channel fuel, a second plurality of channels 562configured to channel oxidants, and a third plurality of channels 564sized to receive heat pipes 554 such that heat pipes 554 are integratedtherein. In the exemplary embodiment, channels 560, 562, and 564 extendlongitudinally along plate 558.

In the exemplary embodiment, heat transfer system 500 includes at leastone storage tank 566 positioned to store water 212 and/or 232. Morespecifically, in the exemplary embodiment, storage tank 566 ispositioned adjacent thermal energy storage module 552 such that water212 and/or 232 is channeled across fuel cell module 202 and/or thermalenergy storage module 552 towards, for example, sink 228 and/or coffeemachine 236 (i.e., external loads). In the exemplary embodiment, thermalenergy storage module 552 is removably coupled to sink 228 and/or coffeemachine 236.

During operation, fuel cell module 202 receives fuel 204 and oxidants206, which are channeled through channels 560 and 562, respectively. Inthe exemplary embodiment, heat pipes 554 absorb heat 214 from fuel cellmodule 202, and PCM 222 stores heat 214.

In the exemplary embodiment, water 212 and/or 232 is channeled acrossthermal energy storage module 552 such that heat 214 is transferred fromthermal energy storage module 552 to water 212 and/or 232 such that atemperature of thermal energy storage module 552 is facilitated to bedecreased and a temperature of water 212 and/or 232 is facilitated to beincreased. That is, in the exemplary embodiment, water 212 and/or 232cools thermal energy storage module 552 to enable thermal energy storagemodule 552 to absorb heat 214 from fuel cell module 202, and thermalenergy storage module 552 heats water 212 and/or 232 for use in, forexample, sink 228 and/or coffee machine 236 (i.e., external loads).Additionally or alternatively, warm water 212 and/or 232 may bechanneled in a reverse direction such that heat 214 is transferred fromwarm water 212 and/or 232 to thermal energy storage module 218 tofacilitate regulating a temperature of thermal energy storage module 552and/or warm water 212 and/or 232 and/or regulating an operatingtemperature of fuel cell module 202.

FIG. 6 is a schematic illustration of another exemplary heat transfersystem 600 that may be used to utilize heat produced by a fuel cellmodule 202 on and/or within aircraft 100 (shown in FIG. 1). In theexemplary embodiment, fuel cell module 202 is integrally coupled to athermal energy storage module 668 such that thermal energy storagemodule 668 substantially circumscribes fuel cell module 202 tofacilitate decreasing heat loss to the ambient environment. Moreover, inthe exemplary embodiment, insulating layer 556 substantiallycircumscribes fuel cell module 202 and/or thermal energy storage module668 to facilitate decreasing heat loss to the ambient environment.

In the exemplary embodiment, fuel cell module 202 includes a pluralityof bipolar plates 670 positioned in series circuit and/or in parallelcircuit. In the exemplary embodiment, each plate 670 has first pluralityof channels 560, second plurality of channels 562, and a third pluralityof channels 672 configured to channel water 212 and/or 232. Morespecifically, in the exemplary embodiment, heat transfer system 500includes at least one storage tank 566 positioned to store water 212and/or 232 such that water 212 and/or 232 may be channeled throughchannels 672 towards, for example, sink 228 and/or coffee machine 236(i.e., external loads). In the exemplary embodiment, channels 560, 562,and 672 extend longitudinally along plate 670. In the exemplaryembodiment, thermal energy storage module 668 is removably coupled tosink 228 and/or coffee machine 236.

During operation, fuel cell module 202 receives fuel 204 and oxidants206, which are channeled through channels 560 and 562, respectively. Inthe exemplary embodiment, water 212 and/or 232 absorbs heat 214 fromfuel cell module 202 as water 212 and/or 232 is channeled through thirdplurality of channels 672.

In the exemplary embodiment, water 212 and/or 232 is channeled acrossthermal energy storage module 668 such that heat 214 is transferred fromthermal energy storage module 668 to water 212 and/or 232 such that atemperature of thermal energy storage module 668 is facilitated to bedecreased and a temperature of water 212 and/or 232 is facilitated to beincreased. That is, in the exemplary embodiment, water 212 and/or 232cools thermal energy storage module 668 to enable thermal energy storagemodule 668 to absorb heat 214 from fuel cell module 202, and thermalenergy storage module 668 heats water 212 and/or 232 for use in, forexample, sink 228 and/or coffee machine 236 (i.e., external loads).

FIG. 7 is a schematic illustration of another exemplary heat transfersystem 700 that may be used to utilize heat produced by a fuel cellmodule 202 on and/or within aircraft 100 (shown in FIG. 1). In theexemplary embodiment, fuel cell module 202 is coupled to a plurality ofheat pipes 774 that extends towards an exterior 776 of aircraft 100. Inthe exemplary embodiment, heat pipes 774 are coupled to fuel cell module202 to facilitate passively transferring heat 214 between fuel cellmodule 202 and exterior 776 such that heat 214 is discharged into theambient environment. In the exemplary embodiment, heat pipes 774 aregenerally similar to heat pipes 220. Alternatively, heat pipes 774 maybe fabricated from any other material and/or include any other fluidthat enable heat transfer system 700 to function as described herein.

FIG. 8 is a schematic illustration of another heat transfer system 800that may be used to utilize heat produced by fuel cell module 202 onand/or within aircraft 100 (shown in FIG. 1). In the exemplaryembodiment, fuel cell module 202 is a semi-passive fuel cell that isoperable using oxygen from a cabin of aircraft 100. More specifically,in the exemplary embodiment, a fan 878 is oriented to discharge air 880across fuel cell module 202 and towards a heat exchanger 882 including afirst tube 884 configured to channel water 212 and/or 232, a second tube886 including PCM 222, and a third tube 888 configured to channel air880. As such, in the exemplary embodiment, heat exchanger 882facilitates removing heat 214 from air 880 and, thus, regulating atemperature within the cabin. In the exemplary embodiment, heatexchanger 882 is portable such that heat exchanger 882 is removable anddischargeable on the ground.

In the exemplary embodiment, tubes 884, 886, and 888 are substantiallycoaxial such that first tube 884 substantially circumscribes second tube886, and second tube 886 substantially circumscribes third tube 888. Inthe exemplary embodiment, a plurality of heat pipes 890 couple secondtube 886 to first tube 884 and/or third tube 888 to facilitate passivelytransferring heat 214 between second tube 886 and first tube 884 and/orthird tube 888. In one embodiment, second tube 886 has a “cascade”configuration such that multiple PCMs 222 are utilized to absorb energyat specific melting points. Alternatively, tubes 884, 886, and 888 mayhave any orientation and/or configuration that enables heat transfersystem 800 to function as described herein.

During operation, air 880 is channeled through fuel cell module 202 andthird tube 888 such that heat 214 is transferred from fuel cell module202 to PCM 222. That is, in the exemplary embodiment, air 880 cools fuelcell module 202. In the exemplary embodiment, PCM 222 stores heat 214and transfers heat 214 towards water 212 and/or 232 to facilitateincreasing a temperature of (i.e., heating) water 212 and/or 232. Thatis, in the exemplary embodiment, PCM 222 heats water 212 and/or 232 foruse in, for example, coffee machine 236 (i.e., an external load).

FIG. 9 is a schematic illustration of another heat transfer system 900that may be used to utilize heat stored in a thermal energy storagemodule 992 on and/or within aircraft 100 (shown in FIG. 1). For example,in the exemplary embodiment, heat transfer system 900 may be used for acoffee machine and/or a water heating device. In the exemplaryembodiment, heat transfer system 900 includes a storage tank 994positioned to store water 232. In the exemplary embodiment, storage tank994 includes a one-way valve 996 that is oriented to discharge water 232through a first conduit 998. In the exemplary embodiment, a secondconduit 1002 is coupled in flow communication with first conduit 998 andis oriented to discharge water 232 towards a vessel 1004.

In the exemplary embodiment, thermal energy storage module 992 includesheat pipes 220 and PCM 222. In the exemplary embodiment, heat pipes 220are adjacent to and/or extend within first conduit 998. In oneembodiment, thermal energy storage module 992 is removably coupled tostorage tank 994. Additionally or alternatively, heat transfer systemmay include heating elements that are coupled to PCM 222. In oneembodiment, at least one insulating layer substantially circumscribesthermal energy storage module 992 to facilitate decreasing heat loss tothe ambient environment. In one embodiment, thermal energy storagemodule 992 is easily movable and weighs less than approximately 15kilograms (kg). More particularly, thermal energy storage module 992 mayweigh less than approximately 10 kg. Even more particularly, thermalenergy storage module 992 may weigh less than approximately 5 kg.Alternatively, thermal energy storage module 992 may be of any weightthat enables heat transfer system 900 to function as described herein.

During operation, heat 214 is stored within PCM 222, and thermal energystorage module 992 is coupled to storage tank 994. In the exemplaryembodiment, water 232 is discharged from valve 996 and channeled throughfirst conduit 998. In the exemplary embodiment, heat pipes 220 transferheat 214 from PCM 222 towards water 232 channeled through first conduit998 as water 232 is channeled through first conduit 998 to facilitateincreasing a temperature of (i.e., heating) water 232. In the exemplaryembodiment, heated water 232 is channeled through second conduit 1002and is discharged towards vessel 1004. In one embodiment, water 232 isheated to be at least approximately 91° C. when discharged from secondconduit 1002. More particularly, water 232 may be heated to be at leastapproximately 95° C. Alternatively, water 232 may be discharged at anytemperature that enables coffee and/or tea to brew and/or water to boil.

FIG. 10 is a schematic illustration of another heat transfer system 1000that may be used to utilize heat stored in a thermal energy storagemodule 1006 on and/or within aircraft 100 (shown in FIG. 1). Forexample, in the exemplary embodiment, heat transfer system 1000 may beused for a coffee machine and/or a water heating device. In theexemplary embodiment, heat transfer system 1000 includes storage tank994 positioned to store water 232. In the exemplary embodiment, storagetank 994 includes one-way valve 996 that is oriented to discharge water232 through first conduit 998. In the exemplary embodiment, secondconduit 1002 is coupled in flow communication with first conduit 998 andis oriented to discharge water 232 towards vessel 898.

In the exemplary embodiment, thermal energy storage module 1006 includesheat pipes 1008, PCM 222, and a heating element 1010. In the exemplaryembodiment, heating element 1010 is coupled to first conduit 998 andsubstantially circumscribes first conduit 998. In the exemplaryembodiment, PCM 222 substantially circumscribes heating element 1010 tofacilitate decreasing heat loss to the ambient environment. In theexemplary embodiment, heat pipes 1008 extend through PCM 222 and intostorage tank 994. In the exemplary embodiment, heat pipes 554 aregenerally similar to heat pipes 220. Alternatively, heat pipes 554 maybe fabricated from any other material and/or include any other fluidthat enable heat transfer system 500 to function as described herein. Inone embodiment, thermal energy storage module 1006 is removably coupledto storage tank 994. In one embodiment, at least one insulating layersubstantially circumscribes thermal energy storage module 1006 tofacilitate decreasing heat loss to the ambient environment. In oneembodiment, thermal energy storage module 1006 is easily movable andweighs less than approximately 15 kg. More particularly, thermal energystorage module 1006 may weigh less than approximately 10 kg. Even moreparticularly, thermal energy storage module 1006 may weigh less thanapproximately 5 kg. Alternatively, thermal energy storage module 1006may be of any weight that enables heat transfer system 1000 to functionas described herein.

During operation, water 232 is discharged from valve 996 and channeledthrough first conduit 998. In the exemplary embodiment, heat 214 istransferred from heating element 1010 towards water 232 channeledthrough first conduit 998 to facilitate increasing a temperature of(i.e., heating) water 232. In the exemplary embodiment, heated water 232is channeled through second conduit 1002 and is discharged towardsvessel 1004. Additionally, in the exemplary embodiment, heat 214generated by heating element 1010 may be stored within PCM 222. In theexemplary embodiment, heat pipes 1008 transfer heat 214 stored withinPCM 222 towards water 232 stored within storage tank 994 to facilitatecapturing heat loss from heating element 1010 to the ambient environmentand/or recycling the captured heat by moving it via heat pipes 1008 tothe water.

FIG. 11 is a schematic illustration of another heat transfer system 1100that may be used to utilize heat stored in a thermal energy storagemodule 1112 on and/or within aircraft 100 (shown in FIG. 1). Forexample, in the exemplary embodiment, heat transfer system 1100 may beused for a coffee machine and/or a water heating device. In theexemplary embodiment, heat transfer system 1100 includes storage tank994 positioned to store water 232. In the exemplary embodiment, storagetank 994 includes one-way valve 996 that is oriented to discharge water232 through first conduit 998. In the exemplary embodiment, heatingelement 1010 is coupled to first conduit 998 and substantiallycircumscribes first conduit 998. In the exemplary embodiment, secondconduit 1002 is coupled in flow communication with first conduit 998 andis oriented to discharge water 232 towards vessel 1004.

In the exemplary embodiment, thermal energy storage module 1112 includesheat pipes 1008 and PCM 222. In the exemplary embodiment, heat pipes 220extend between PCM 222 and storage tank 994. In one embodiment, thermalenergy storage module 1112 is removably coupled to storage tank 994 suchthat thermal energy storage module 1112 is chargeable (i.e., heated)remote from storage tank 994. In one embodiment, at least one insulatinglayer substantially circumscribes thermal energy storage module 1112 tofacilitate decreasing heat loss to the ambient environment. In oneembodiment, thermal energy storage module 1112 is easily movable andweighs less than approximately 15 kg. More particularly, thermal energystorage module 1112 may weigh less than approximately 10 kg. Even moreparticularly, thermal energy storage module 1112 may weigh less thanapproximately 5 kg. Alternatively, thermal energy storage module 1112may be of any weight that enables heat transfer system 1100 to functionas described herein.

During operation, heat 214 is stored within PCM 222, and thermal energystorage module 1112 is coupled to storage tank 994. In the exemplaryembodiment, heat pipes 1008 transfer heat 214 stored within PCM 222towards water 232 stored within storage tank 994 to facilitateincreasing a temperature of (i.e., heating) water 232. In the exemplaryembodiment, water 232 discharged from valve 996 and channeled throughfirst conduit 998. In the exemplary embodiment, heat 214 generated byheating element 1010 is absorbed by water 232 channeled through firstconduit 998 to facilitate increasing a temperature of (i.e., heating)water 232 and/or reducing an electrical demand on heating element 1010.In the exemplary embodiment, heated water 232 is channeled throughsecond conduit 1002 and is discharged towards vessel 1004.

FIG. 12 is a schematic illustration of another heat transfer system 1200that may be used to utilize heat stored in a thermal energy storagemodule 1214 on and/or within aircraft 100 (shown in FIG. 1). Forexample, in the exemplary embodiment, heat transfer system 1200 may beused for a coffee machine and/or a water heating device. In theexemplary embodiment, heat transfer system 1200 includes storage tank994 positioned to store water 232. In the exemplary embodiment, storagetank 994 includes one-way valve 996 that is oriented to discharge water232 through first conduit 998. In the exemplary embodiment, heatingelement 1010 is coupled to first conduit 998 and substantiallycircumscribes first conduit 998. In the exemplary embodiment, secondconduit 1002 is coupled in flow communication with first conduit 998 andis oriented to discharge water 232 towards vessel 1004.

In the exemplary embodiment, thermal energy storage module 1214 includesPCM 222 that substantially circumscribes storage tank 994. In oneembodiment, thermal energy storage module 1214 is removably coupled tostorage tank 994 such that thermal energy storage module 1214 ischargeable (i.e., heated) remote from storage tank 994. In oneembodiment, at least one insulating layer substantially circumscribesthermal energy storage module 1214 to facilitate decreasing heat loss tothe ambient environment. In one embodiment, thermal energy storagemodule 1214 is easily movable and weighs less than approximately 15 kg.More particularly, thermal energy storage module 1214 may weigh lessthan approximately 10 kg. Even more particularly, thermal energy storagemodule 1214 may weigh less than approximately 5 kg. Alternatively,thermal energy storage module 1214 may be of any weight that enablesheat transfer system 1200 to function as described herein.

During operation, heat 214 is stored within PCM 222, and thermal energystorage module 1214 is coupled to storage tank 994. In the exemplaryembodiment, heat 214 stored within PCM 222 is transferred towards water232 stored within storage tank 994 to facilitate increasing atemperature of (i.e., heating) water 232. In the exemplary embodiment,water 232 discharged from valve 996 and channeled through first conduit998. In the exemplary embodiment, heat 214 generated by heating element1010 is absorbed by water 232 channeled through first conduit 998 tofacilitate increasing a temperature of (i.e., heating) water 232. In theexemplary embodiment, heated water 232 is channeled through secondconduit 1002 and is discharged towards vessel 1004.

FIG. 13 is a schematic illustration of another heat transfer system 1300that may be used to utilize heat stored in a thermal energy storagemodule 1316 on and/or within aircraft 100 (shown in FIG. 1). In theexemplary embodiment, heat transfer system 1300 includes, for example,oven 446 (i.e., an external load). In the exemplary embodiment, thermalenergy storage module 1316 includes PCM 222, heating elements 1318, anda plurality of heat pipes 1320 extending between PCM 222 and oven 446.In the exemplary embodiment, PCM 222 substantially circumscribes oven446 to facilitate decreasing heat loss to the ambient environment.Moreover, in the exemplary embodiment, at least one insulating layer1322 substantially circumscribes thermal energy storage module 1316 tofacilitate decreasing heat loss to the ambient environment. In oneembodiment, thermal energy storage module 1316 is removably coupled tooven 446. In one embodiment, thermal energy storage module 1316 iseasily movable and weighs less than approximately 15 kg. Moreparticularly, thermal energy storage module 1316 may weigh less thanapproximately 10 kg. Even more particularly, thermal energy storagemodule 1316 may weigh less than approximately 5 kg. Alternatively,thermal energy storage module 1316 may be of any weight that enablesheat transfer system 1300 to function as described herein.

In the exemplary embodiment, heating elements 1318 and/or heat pipes1320 are arranged in a spaced configuration within PCM 222 to facilitateincreasing heat transfer between PCM 222 and oven 446. In the exemplaryembodiment, heat pipes 1320 includes a plurality of fins 1324 thatfacilitate increasing a surface area of heat pipes 1320 such that heattransfer between PCM 222 and oven 446 is increased. Alternatively,heating elements 1318 and/or heat pipes 1320 may be arranged in anyconfiguration that enables heat transfer system 1300 to function asdescribed herein.

During operation, heat 214 is generated by heating elements 1318 and/orstored within PCM 222. For example, in one embodiment, the stored heatmay be generated when aircraft 100 is grounded. In the exemplaryembodiment, heat pipes 1320 transfers heat 214 towards oven 446 tofacilitate increasing a temperature of (i.e., heating) oven 446.

The embodiments described herein relate generally to heat transfersystems and, more particularly, to methods and systems for utilizingheat produced by a fuel cell module and/or utilizing heat stored in athermal energy storage module. The embodiments described hereinfacilitate increasing fuel cell efficiency for use in an airplane galleyand/or decreasing a quantity of airplane generated power required tooperate the airplane during flight. As such, the embodiments describedherein facilitate decreasing an amount of power used by galleys throughenergy storage, use of combined heat and power from fuel cells, andefficient transfer of the heat from the fuel cell to galley insertloads.

Exemplary embodiments of methods and systems for transferring, storing,and/or utilizing heat in an aircraft environment are described above indetail. The methods and systems are not limited to the specificembodiments described herein, but rather, components of systems and/orsteps of the method may be utilized independently and separately fromother components and/or steps described herein. Each method step andeach component may also be used in combination with other method stepsand/or components. Although specific features of various embodiments maybe shown in some drawings and not in others, this is for convenienceonly. Any feature of a drawing may be referenced and/or claimed incombination with any feature of any other drawing.

This written description uses examples to disclose the embodiments,including the best mode, and also to enable any person skilled in theart to practice the embodiments, including making and using any devicesor systems and performing any incorporated methods. The patentable scopeof the disclosure is defined by the claims, and may include otherexamples that occur to those skilled in the art. Such other examples areintended to be within the scope of the claims if they have structuralelements that do not differ from the literal language of the claims, orif they include equivalent structural elements with insubstantialdifferences from the literal language of the claims.

1-16. (canceled)
 17. A method of operating a heat transfer system, saidmethod comprising: coupling a plurality of heat pipes to a load;transferring heat to a thermal energy storage module including aphase-change material, wherein the heat is stored in the thermal energystorage module; coupling the thermal energy storage module to theplurality of heat pipes to facilitate transferring heat towards theload.
 18. A method in accordance with claim 17 further comprisingproviding electricity to a plurality of heating elements oriented totransfer heat towards the phase-change material.
 19. A method inaccordance with claim 17, wherein coupling the thermal energy storagemodule further comprising removably coupling the thermal energy storagemodule to at least one of the load and the plurality of heat pipes. 20.A heat transfer system comprising: a load; a plurality of heat pipescoupled to said load; and a thermal energy storage module coupled tosaid plurality of heat pipes to facilitate transferring heat towardssaid load, said thermal energy storage module comprising a phase-changematerial.
 21. A heat transfer system in accordance with claim 20,wherein said thermal energy storage module further comprises a pluralityof heating elements that are oriented to transfer heat towards saidphase-change material.
 22. A heat transfer system in accordance withclaim 20 further comprising an insulating layer substantiallycircumscribing said thermal energy storage module.
 23. A heat transfersystem in accordance with claim 20, wherein each of said plurality ofheat pipes further comprises a plurality of fins.
 24. A heat transfersystem in accordance with claim 20, wherein said thermal energy storagemodule is removably coupled to at least one of said load and saidplurality of heat pipes.
 25. A method of operating a heat transfersystem, said method comprising: transferring heat to a thermal energystorage module including a phase-change material, wherein the heat isstored in the thermal energy storage module; and circumscribing thethermal energy storage module about the load to facilitate transferringheat towards the load.
 26. A method in accordance with claim 25 furthercomprising providing electricity to a plurality of heating elementspositioned to transfer heat towards the phase-change material.
 27. Aheat transfer system comprising: a load; and a thermal energy storagemodule circumscribing said load to facilitate transferring heat towardssaid load, said thermal energy storage module comprising a phase-changematerial.
 28. A heat transfer system in accordance with claim 27,wherein said thermal energy storage module further comprises a pluralityof heating elements that are positioned to transfer heat towards saidphase-change material.
 29. A heat transfer system in accordance withclaim 27 further comprising an insulating layer substantiallycircumscribing said thermal energy storage module.
 30. An aircraftcomprising: a galley comprising at least one load positioned therein; afuel cell module configured to produce heat and water; and a heattransfer system comprising: a first plurality of heat pipes; and athermal energy storage module coupled to said first plurality of heatpipes to facilitate transferring the heat produced by said fuel cellmodule towards said at least one load, said thermal energy storagemodule comprising a phase-change material.
 31. The aircraft inaccordance with claim 30, wherein said heat transfer system furthercomprises a second plurality of heat pipes are coupled between said fuelcell module and said thermal energy storage module such that heatproduced by said fuel cell module is stored within the phase-changematerial.
 32. The aircraft in accordance with claim 31 furthercomprising a water storage tank, wherein said thermal energy storagemodule is coupled to said water storage tank such that the heat storedwithin the phase-change material is transferred towards water stored insaid water storage tank.
 33. The aircraft in accordance with claim 30,wherein said heat transfer system further comprises a conduit thatcouples said fuel cell module to said thermal energy storage module,said conduit configured to channel the water produced by said fuel cellmodule through said thermal energy storage module, thereby forming astream of heated water, said conduit further extending from said thermalenergy storage module for channeling the stream of heated water towardssaid at least one load.
 34. The aircraft in accordance with claim 33,wherein said at least one load configured to receive the stream ofheated water comprises at least one of a sink or a coffee machine. 35.The aircraft in accordance with claim 30, wherein said first pluralityof heat pipes are coupled to said at least one load such that the heatproduced by said fuel cell module is transferred towards said at leastone load.
 36. The aircraft in accordance with claim 30 furthercomprising an insulating layer substantially circumscribing said thermalenergy storage module.